INTELLIGENCE IN INSECTS 195 



territory in a nearly direct line to her hole we say nearly 

 direct, for there was almost invariably some slight mistake 

 in the direction which made a little looking about necessary 

 before the exact spot was found. 



"After days passed in flying about the garden going up 

 Bean Street and down Onion Avenue, time and time again 

 one would think that any formal study of the precise locality 

 of a nest might be omitted, but it was not so with our wasps. 

 They made repeated and detailed studies of the surroundings 

 of their nests. Moreover, when their prey was laid down 

 for a moment on the way home, they felt the necessity of 

 noting the place carefully before leaving it." Similar 

 11 locality studies " varying more or less in character, are made 

 by many other genera of wasps, but after a number of 

 flights from home the preliminary circling about becomes 

 gradually reduced, and finally the insects fly away in a 

 straight line. 



The role of visual memory is shown in the way in which 

 wasps are disconcerted by a change in the region about their 

 nests made during their absence. "Aporus faciatus," say 

 the Peckhams, " entirely lost her way when we broke off 

 the leaf that covered her nest, but found it, without trouble, 

 when the missing object was replaced. All the species of 

 Cerceris were extremely annoyed if we placed any new object 

 near their nesting places. Our Ammophila refused to make 

 use of her burrow after we had drawn some deep lines in the 

 dust before it. The same annoyance is exhibited when 

 there is any change made near the spot upon which the prey 

 of the wasp, whatever it may be, is deposited temporarily." 

 Even a slight change so disconcerted the wasps that they were 

 obliged to hunt for a long time before recovering their prey. 



Belt has recorded a very interesting case of a wasp, Polistes 

 carnifex, which had caught a caterpillar too large to be carried 



